Node.js is a free and open-source, cross-platform JavaScript run-time environment for executing JavaScript code server-side. It is quite popular to write web apps. This tutorial shows how to install Node.js and vtop (a better top like tool written in Node.js) app on an Ubuntu Linux 16.04 LTS server.
From the tutorial page:
How do I install Node.js (“Javascript for server-side programming”) on an Ubuntu Linux 16.04 LTS server using command line only option?
The vtop is a graphical activity monitor for the command line written in Node.js. How do I install vtop on my Linux server?